Sam quoted The Left Hand of Darkness by Ursula K. Le Guin (Hainish Cycle)
On the planet Winter, there is no gender. The Gethenians can become male or female …
Predictions are uttered by prophets (free of charge); by clairvoyants (who usually charge a fee, and are therefore more honored in their day than prophets); and by futurologists (salaried). Prediction is the business of prophets, clairvoyants, and futurologists. It is not the business of novelists. A novelist's business is lying.
— The Left Hand of Darkness by Ursula K. Le Guin (Hainish Cycle)
From the introduction.